#47: Confirmation Bias

Hey there! Let’s keep discussing cognitive biases, and today, we will focus on confirmation bias.

Confirmation bias is the tendency to search for, interpret, favor, and recall information in a way that confirms or supports a prior assumption or belief. It affects all of us, often without even realizing it.

What are the impacts? When we make an assumption:

1. We might only select information that supports this assumption.

2. We might mentally ignore or dismiss information that would discard this assumption.

3. We might interpret ambiguous information in a way that confirms this assumption.

Think about someone who believes in a conspiracy theory, like flat-Earth believers¹:

1. They seek out content (videos, blogs, etc.) that support the theory.

2. They dismiss scientific evidence or expert opinion that debunks it.

3. They interpret ambiguous observations (e.g., observing the horizon from the ground is seemingly flat) as proof that the Earth is flat.

Where can we observe this bias in our work? Let’s discuss two concrete examples.

When troubleshooting an incident, we often start with an assumption; for example: “I think the app crashed due to a spike in user requests“. It’s natural to begin by looking at dashboards and metrics that might validate this theory; this isn’t the confirmation bias yet. However, here’s when the bias comes in: